Antiskid device



June 23, 1936. E. COENNING ANTISKID DEVICE Filed May 11, 1952 71mm 606mm Patented June 23, 1936 PATENT OFFICE ANTISKID DEVICE Ernst Cocnning, Berlin-C harlottenburg, Germany Application 8 Claim.

This invention relates to a removable anti-skid covering for auto tyres.

According to the invention there are arranged on the removable anti-skid covering several rows oi. projecting cupped projections of elastic material,,for example rubber. Further, according to the invention, in the sides of the covering, double wire rings which are open at one point are inserted flat. The opening of each of these rings is bridged over by a tensioning link so that by means of this link the covering can be securely stretched over the tyre. The specially shaped rubber cupped porjections acting as suction members give specially good protection against skidding and prevent the vehicle from skidding especially well on wet asphalt. The provision of these suction members on a removable cover is important because it makes it possible to protect the suction members'from the friction of the road surface when'travelling' on rough country roads, or removing the cover so that the suction members remain in good order for causes of actual danger, that is, for wet streets. Moreover, the arrangement on a separate anti-skid covering makes it possible to combine the suction members with any desired shape of tyre so that worn tyres can be made useful again by applying the antiskid covering according to the invention.

The invention is illustrated by way of example in the accompanying drawing.

Fig. 1 shows a cross-section through a tyre provided with the cover.

Fig. 2 is a side elevation of Fig.1.

Fig. 3 shows the cover with the anti-skid projections lying in the mold. v

Fig. 4 is a plan of the anti-skid cover provided with hollowed anti-skid members.

'The anti-skid covering I, acording to the invention, is provided with several rows of cupped projections 2 consisting of rubber and having their edges made flexible but sufliciently strong so that when the cupped projections are flattened by being pressed against the roadway, a'vacuum is produced inside which causes the 'wheel to be sucked against the ground and consequently opposes the skidding which is liable to occur in wet weather.

In each side 3 of the covering is laid a double wire ring 4 which is open at one point, namely, at I. In this constructional example, the wire double ring is formed of a single wire in such a manner that the wire forms a narrower and wider ring which at their ends are connected together by transverse wire parts 8. In these transverse parts 6, which are at a distance apart,

May 11, 1932, Serial No. 610,677 Germany December 22, 1931 a tensioning link I is engaged which when tightened stretches the anti-skid cover which is placed round the tyre.

Each of the cupped projections 2 is integral with the tread of the covering or auxiliary casing 5 I and its cross-area is considerably less than its altitude to provide a" broad flat disc-like structure. The projection has an annular recess extending around its base part adjacent to the tread and its wall part is flared outwardly and 10 gradually decreases in thickness toward its edge.

A tread provided with the cupped projections is particularly adapted to prevent skidding on fiat slippery surfaces, such as wet asphalt pavements. When the load presses a cupped projection against an opposing surface, the wall part is compressed and spread outwardly so that there is considerable area of contact between the wall flange and the opposing surface. When the load is initially applied to the cupped projection, air 20 is forced from the hollow of the projection; as the tread turns to the rear during the forward movement of the vehicle, the projection tends to lift'from the opposing surface, but the resulting suction holds the projection momentarily in 25 contact with the surface and thereby prevents slipping. .The large area of contact provided by the expanded and flattened wall part tends to maintain the suction action. The restricted base part increases the flexibility of the wall part so that the latter can move as a whole to accommodate itself to the change in the direction of the thrust of the load as the tread moves with relation to the opposing surface, thereby prolonging the flat contact of the projection with the opposing surface. As the tread turns to the rear, in the forward progress of the vehicle, a number of the projections simultaneously effect the suction action and thereby prevent slipping to a considerable extent. suiiiciently far apart to permit their expansion under pressure without contacting. The staggered arrangement economizes space in positioning the cupped projections.

What I claim is:

1. An anti-skid device for pneumatic tires comprising a tread and a plurality of fiat discshaped resilient projections arranged in rows on the tread in interspaced relation, each of said projections having an annular recess extending 50' around its base part adjacent to the tread, and each of said projections having a conically shaped recess extending into the same, said recesses having each a mouth diameter greater than its depth and imparting to the projection 5 The cupped-projections are spaced o an outwardly flared wall, comparatively thick at its inner part and tapering toward its outer part.

2. An anti-skid device for pneumatic tires comprising a tread and resilient cup-shaped projections arranged on the tread in spaced relation in several rows, each of said projections having a cavity in the form of a shallow cone narrowing into an apex at the bottom, the mouth diameter of said cavity being greater than its depth.

' 3. An anti-skid device for pneumatic tires comprising a tread and resilient cup-shaped projec-,

tions arranged on the tread in spaced relation in several rows, each of said projections having a cavity in the form of a shallow cone narrowing into an apex at the bottom, the mouth diameter of said cavity being greater than its depth and the outer edges of the cone merging gradually into a surface at right angles. to the radius of the tire passing therethrough at any given point.

4. An anti-skid device for pneumatic tires comprising a tread and resilient cup shaped projections arranged on the tread in spaced relation, each of said projections having a cavity in the form of a shallow cone the mouth diameter of which is greater than its depth and having a restricted base part adjacent to the tread and having a wall part flared outwardly from the base part, and with all portions of the outer edges extending outwardly beyond the periphery of the base, said wall part gradually decreasing in thickness from the base part toward the edge of the wall part which terminates in a circular line, and said cup shaped projections being spaced sufficiently apart to permit spreading outwardly of the individual projections as they press against an opposed surface.

5. An anti-skid device for pneumatic tires comprising a detachable flexible casing adapted to fit over the tire of a wheel, means for holding the detachable casing on the tire, said casing including a tread to correspond with the tread of the tire and resilient cup shaped projections arranged on the casing tread in staggered spaced relation, each of said projections having a cavity in the form of a shallow cone the mouth diameter of which is greater than its depth and having a restricted base part adjacent to the casing tread and having a wall part flared outwardly from the base part, the outer portion of the opening being of a larger diameter than the base part, said wall part gradually decreasing in thickness from the base part toward the outer edge of the wall which terminates in a thin line and said cupped projections being spaced sutflciently apart to permit spreading of the individual projections as they press against an opposed surface.

6. An anti-skid device for pneumatic tires comprising a detachable casing adapted to flt over the tire of a wheel, said casing comprising a tread portion having thereon cup shaped munded rim projections staggered on the tread relatively to each other, each projection having a cavity in the form of a shallow cone the mouth diameter of which is greater than its depth comprising a base portion and outwardly and laterally flared portion, each outwardly flared portion having its outward rounded end extending laterally beyond the periphery of the circular base portion, whereby as a. projection is pressed against a surface the outwardly flared end will facilitate the flattening of the circular body portion of each projection to form a vacuum as pressure is removed and it tends to resume its normal position and thus fasten the tread to the opposing surface.

7. An anti-skid device for pneumatic tires comprising a tread and resilient cup-shaped projections arranged on the tread in spaced relation in several rows, each of said projections having a cavity in the form of a shallow cone narrowing into an apex at the bottom, said cavity being obtuse in section due to its flaring contour.

8. An anti-skid device for pneumatic tires comprising a tread and resilient cup-shaped projections arranged on the tread in spaced relation ERNST COENNDIG. 

